The present invention relates generally to the field of embedded antennas, such as those used to receive radio frequency (RF) signals. In particular, the invention relates to a novel technique for connecting an embedded antenna to remote circuitry, such as for receiving and processing signals from RF tags, and other signals sources.
A growing number of applications make use of wireless antenna for receiving signals from a variety of sources. A number of such applications involve the use of RF sources, tags, antenna and associated circuitry for detecting the presence of, or communicating data to and from remote devices with radio frequency electromagnetic waves. For example, in a growing number of inventory and material handling applications, passive RF tags are placed on components, including the components themselves, packaging, and associated documentation. The RF tags are capable of identifying the components when the component is placed within a desired or specific range of an RF antenna. The source of the data may also be an active source, such as a powered computer chip or other device. In general, the antenna is specifically designed, such as by the choice of materials and geometries to tune its electromagnetic properties to the frequency of the source. Thus, once properly tuned, the antenna can detect, send and receive signals at the desired frequency.
A challenge in implementing radio frequency wireless systems is in the design of the antenna, and the placement of the antennae in the systems. For example, advancements have been made in the formation of embedded antenna, such as antennae used in decals, labeling, and even within laminated or multi-layer structures. In certain applications, where the antenna is at an upper-most location in packaging, the connection of transmitting/receiving circuitry to the antenna does not pose a particular problem. However, where an antenna is embedded in a multi-layer structure, connection to the antenna becomes problematic.
Circuitry coupled to passive antennae, such as RF antenna, may include various filtering, impedance matching, and sensing circuitry. For example, depending upon the antenna design, the precise frequency matched to the antenna may need to be tuned, such as by the use of tuning capacitors. Signals received by the antenna, and passed through the tuning circuitry, may be further filtered, digitized, amplified, or otherwise processed to convert the signal to a useable form. Ultimately, the received or transmitted signals originating from or applied to specialized circuitry and systems, such as to monitor the presence, number, placement, and other parameters related to the particular components to which the RF tags or senders are secured must be coupled to a resonant antenna.
There is, at present, a particular need for techniques for interfacing or connecting embedded antenna, such as RF antennae with external circuitry. One such need exists in the field of laminated structures, in which embedded antennae can be formed on one of the laminated layers, and the antennae interfaced with filtering, impedance matching, amplification, or other data acquisition circuitry by means of a simple and reliable interconnection.